Fuse switch



April 28, 1953 v. HELLSTERN 2,636,954

FUSE SWITCH Filed Sept. 18, 1950 -3 Sheets-Sheet 2 y 17 ns. 5%

INVENTOR. VERNON HELLSTERN April 1953 v. HELLSTERN 2,636,954

FUSE SWITCH Filed Sept. 18, 1950 3 Sheets-Sheet 3 IN V EN TOR.

VERNON HELLSTERN Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE FUSE SWITCH Application September 18, 1950, Serial No. 185,375

7 Claims. I

This invention relates generally to fuse switches, and more specifically to an improved housed fuse switch which includes a switch housing having a door that supports a fuse cartridge adapted on rupture of the fuse link of the switch to drop bodily out of the operative fusing position and swing outwardly and downwardly with the door from the closed to the open position of the door, the predominantobject of the invention being to provide an improved switch of this type which, because of its unique construction and" the novel arrangement of its parts, is capable of performing its intended function in an improved and highly efficlent manner.

l is a vertical section taken through the improved fuse switch of this invention, and showing portions of the door and the fuse cartridge by broken lines in their dropped out positions.

Fig. 2 is a horizontal section taken on line 2--2 of Fig: 1.

Fig. 3 is afragmentary vertical section taken on line 3-3-' of Fig: 1.

Fig. 4; is" an inverted planview of the fuse switch-illustrated in Fig. I.

Fig. 5' is a horizontal section taken on line 5-'5' of Fig. 1.

Fig. dis a fragmentary vertical section taken on line 6-6 of" Fig. 1.

Fig. 7 is a: fragmentary el'ev-ati'onal view viewed fromline T- l of Fig. 1'.

Fig. 8= is a fragmentary'section taken-on: line I -8 of Fig. '7'.

-' Fig. 9* is a horizontal section takenon line 9"8*of'Fig; 1.

Fig. 10'is a f'ragmentarysection ofar portion of theswitch.

Fig. 11- is a' similarview' of another portion of the switch.

In the drawings, wherein is shown for." purposes of? illustrations; merely; one embodiment of the invention; A designates in Fig; 1 the improved fuse-switch generally; The iinproved fuse switch A: includes. ahousing I which is open at its front and-bottom, said housing being provided at its front with a door'2' which is hinged-with respect to the housing amanner to be hereinafter set forth: The-housing i is formed of porcelain, or othersu-itable electrical? insulating material, and theuzear wall: ofz said? housing in vertical: section is; shaped, as: is shown" in Fig: la. Formed transversely through the rear wall? of the'h'ousingi I'- adjacentto thettop-of the housing is an open ng 3; andformed?transverselygthroughisaid rear'wall' adj acentw-towthe bottom ofthe housingris asimilar; opening-'4. The openings; flrand 4z areropen atthe outer side faces of the housing, and smaller openings 5 and 6 extend respectively from the openings 3 and 4 to the inner face of the rear wall of the housing. The rear wall of the housing I at the appproximate vertical center of said housing is of considerably greater thickness than the remainder of said rear wall, and formed through this portion of the rear wall is an opening I which is open at the opposed outer side faces of the housing and is of greater diameter than the openings 3 and 4. In the case of the opening 1 an opening 8 of less diameter extends from said opening rearwardly to the rear face of the rear wall of the housing I.

Arranged in contact with the rear face of the rear wall of the housing I' is a hanger 9 which serves as means for attaching the fuse switch A to a' support when the fuse switch is in use, and said hanger is secured to the housing I by a bolt l0 whose head engages a washer associated with the hanger assembly and which passes through the opening 8 and through an opening formed through the hanger which is alined with the opening 8. The inner portion of the bolt 10 extends into the opening 7, and a substantially V- shaped element H is located within this opening' in contact with the wall thereof, said V- shaped element having an opening formed therethrough through which the bolt extends, and a nut i2 which is mounted on the inner end portion of the bolt is screwed into close contact with said V-shaped element so as to securely fix the hanger to the housing.

Located within the openings 3 and 4 are terminals l3 and I4 to which are attached conductors Cu; and Cb of the electrical circuit in which the fuse switch is interposed. Each of the terminals i3 and I'll comprises an elongated sleeve l5 which is shaped in cross-section as is shown in Fig. 1, each of said terminals being of slightly greater thickness at its base than elsewhere. Associated with the terminal 13 is an upper contact l6 and associated with the terminal I4- is a lower contact ll. The upper contact I6 comprises a base element l3 formed of suitable resilient material havin'g'a facing 18' of copper, or other good electrical conductive material, said upper contact being shaped as is shown in Fig. 1. That is to say, the upper contact includes a portion I; which extends parallel relative to a face I of the rear wall of the housing I, an intermediate forwardly and downwardly inclined portion I66, and an outer, forwardly extended portion I60 whose forward end portion: Hid is curved outwardly and upwardly (Fig. l-).

Interposed between the portion IBa of the upper contact and the face I of the rear wall of the housing I is an upwardly extended portion IQa of a resilient latch member I9, said latch member having a forwardly extended leg portion I9b which is provided with a keeper portion I90 and whose outer end portion ISId is curved upwardly and outwardly. The upper contact l6 and the latch member I9 are secured in place within the upper portion of the housing I by means of a bolt 28 whose shank portion extends through alined openings formed through the portion Ifia of the upper contact It and the portion I9a of the latch member I9, the screwthreaded end portion of said bolt 20 being screwed into a screwthreaded opening formed in the base portion of the terminal I3 (Fig. 1), and there being a washer 2| interposed between the head of the bolt 20 and a forward face portion of the portion [6a of the upper contact I S. In order to securely fix the terminal I3 to the conductor Ca a pair of clamping bolts 22 are provided. The shanks of these clamping bolts extend through openings formed through the rear wall of the housing I and screwthreadedly project through screwthreaded openings formed through the base portion of the terminal I3, the outer ends of said bolts forcibly engagin the conductor Ca, as is shown to good advantage in Fig. 2, and the heads of said bolts 22 engaging washers 23 which contact with a plate 24 that contacts with the face I of the housing I.

The lower contact I I comprises a strip of resilient material which is a good conductor of electricity, said strip of material having a lower portion I la, an upwardly and forwardly inclined, intermediate portion Ilb, and an upper portion He. The lower portion I'Ia of the lower contact engages a plate 25 which contacts with a face Ia of the housing I and this plate and the portion Ila of the lower contact I I have alined openings formed therethrough through which the shank of a bolt 26 extends, the screwthreaded end portion of the shank of said bolt 26 being screwed through a screwthreaded opening formed through the base portion of the terminal I4, and the head of said bolt 26 engaging a washer which contacts with the forward face of the portion Ila of the lower contact I!. Also, the terminal I4 has associated therewith a pair of clamping bolts 27 (Fig. which are arranged as are the clamping bolts 22 associated with the terminal I3, as has been previously explained herein, said clamping bolts 2'! serving to secure the conductor Cb to the terminal I4.

The door 2 of the'fuse switch of the present invention has secured to the upper portion thereof a bracket structure 28 which is formed by a member 29 that isfixed to the inner face of the door by fastening devices 29', and a member 30 which is secured to the member 29 by means of fastening devices 33, the bracket structure and the door preferably being formed from electrical non-conductive material. Also, secured to the lower portion of the door 2 at the inner face thereof is a second bracket member 3| which is of inverted L-shaped formation, there being a bracket portion 3 la which contacts with the inner face of the door 2, and an upper portion 3Ib that extends inwardly of the housing I from the upper end of the bracket portion 3 la and which is provided with an opening 32 formed therethrough.

The brackets 28 and 3I support a fuse cartridge 33 which includes a tube structure 34 compris- 4 ing an outer tube Ma formed of Bakelite, or other material possessing required characteristics, and an inner tube 342; formed of horn fiber, said tube structure being extended through the opening 32 of the portion 3Ib of the bracket 3|. The member 30 of the bracket structure 23 is provided with a screwthreaded opening 35 into which is screwed the screwthreaded shank 36 of a head 36, said head being provided with a rearwardly projected extension 3'! having latching pins 33 extended outwardly from opposite sides thereof. The head 36 is provided with a screwthreaded opening 39 formed therein which receives the externally screwthreaded upper portion of the outer tube 34a of the tube structure 34, as is shown in Fig. 1, said screwthreaded opening 39 being located largely in the shank 36' of said head 36. The head has an opening 49 formed therein which is of approximately the same diameter as the bore of the inner tube 34b of the tube structure, as is shown in Fig.1, and said opening 49 communicates with the bore-of said inner tube 34b. Also,the opening 40 communicates at its upper end with a screwthreaded opening 4| formed in the head 36 which is of greater diameter than the opening 43.

The head 33 is formed of electrical conductive material and a fuse link 42 is extended through the opening 4!! of said head and through the tube structure 34, said fuse link having a flanged cap 43 at its upper end the flange of which rests on a shoulder 44 within the head 36. The flange of the flanged cap 43 is forced into close contact with the shoulder 44 by a screwthreaded plug 45 which is screwed into the screwthreaded opening 4| of the head 36, said plug being formed of electrical conductive material, and the tail portion of the fuse link extends from the lower open end of the tube structure 34.

Referring now to the lower bracket 3 I on the door 2 of the housing I, it will be noted that the portion 3Ia of said bracket is provided with opposed ears 46 (Figs. 1 and 6), and these-ears hingedly support a hinge member 41. The hinge member comprises opposed side walls 41a which are joined by an integral bridge portion 41b, the upper portions of said opposed, side walls being secured by pivot elements 48 to the ears 46, and the lower portions of said opposed, sidewalls being provided with hook-shaped portions 49 which engage fixedhinge elements 58. The hinge elements 50 are in rod form and portions thereof are fixedly seated, with the aid of cement 5l,;in openings formed in wall portions of the housing I. The bridge portion 41b of the hinge member 41 has fixed thereto a cartridge contact 52 which is shaped as is shownto good advantage in Fig. 1; that is to say, said cartridge contact is provided with a lower portion 52a which rests against and is secured to the bridge portion 41b of the hinge member 41, an intermediate inclined portion 52b which extends from the upper end of said portion 52a, and an upper, curved portion 520. The cartridge contact 52 has associated therewith a block 53 which is shaped as is shown in Fig. 1, there being a headed screw-threaded element 54 which is extended through alined openings formed through the bridge portion 41b of the hinge member 47 and through the block 53, and said element 54 has a fuse link binding nut 55 mounted on it screwthreaded end portion. At its lower end portion the bracket 3| is provided with a pair of opposed ears 56 which support a pivot rod 57 (Fig. 4), and this pivot rod 5'! in turn supports for pivotal movement a latch element :58. The latch element 58 is of substantially zu-shaped configuration, having opposed side .portions 58a and abridge portion 58b, and the opposed side portions have fixed thereto outwardly extended bearing elements .55 through which the pivot rod 51 extends. Also, a torsional coil spring 60 embraces a portion of the pivot rod 5-! which is located between the side portions 58a of the -latch element, one end portion of said torsional coil spring contacting with the bracket 3] while the opposite end portion of said torsional coil spring contacts with a part of the latch element 58. Because of the arrangement of the torsional coil spring 60 as described above, said torsional coil spring tends to move the rear end of the latching element downwardly. The bridge portion 58b of the latch element :53 has formed thereon a pair of spaced ears .6] which support a pivot rod .62. The pivot rod in turn supports an arm 63 for pivotal movement with respect thereto,

there being a torsional coil sprin 54 arranged in embracing relation with respect to said pivot rod 62 with one end portion of said coil spring contacting with the bridge portion 58c of the latch element 58, and the other end portion of said coil spring contacting with the arm '63. The arm 63 at its free end is provided with an arcuate edge 53' (Fig. ,4) and at that end thereof said arm is channel-shaped, as is shown in Fig. 6, and said arm 63 includes a curv d po n 6 which partially embraces the torsional coil spring 64.

In the normal use of the improved fuse switch of this invention, the door and fuse cartridge assembly is in its closed pos tion with respect to the housing 1, in which position the latch pins 38 are seated in the keeper portion [90 of the latching member Hi, whereby the upper portion of the door is retained in its closed position. Also, in such closed position of the door and the fuse cartridge assembly the upper contact l6 contacts mechanically and electrically with the plug 45 at the top of the fuse cartridge. The intact fuse link extends downwardly through tube structure of the fuse link and extends from the open lower end of said tube structure, the rear end portion of the latch element 58 being disposed in its elevated positio where the bridge portion 58b of said latch member engages behind the bridge portion Nb of the hinge member 41, as is shown in Figs. 1 and 8. Additionally, the arm 63 is extended forwardly from the pivot rod 82 and the tail portion of the fuse link which extends out of the lower open end of the tube structure of the fuse cartridge ext-ends lon itudinally of the arm 63 so as to hold. said arm 53 in its forwardly extended position against the force exerted by the torsional coil spring 64 which tends to move the forward end portion of said arm 53 downwardly, and so as to retain the latching element in its elevated position where it latches behind the bridge portion All; of the hinge member 47, the end portion of the tail of the fuse link being clamped by the link binding element 55. With the parts of the fuse switch in the positions described the cartridge contact 52 is in electrical contact with the lower contact 5'! of the housing and the electrical path through the switch is from the conductor Ca to the upper contact {5 by way of the upper terminal !3 and the bolt ft, from the upper contact by way of the plug 45. the fuse link 42, the block 55.5 and the cartridge contact 52 to the lower contact ll of the housing and from said lower contact i! to the conductor Cb by way of the bolt 25 and the lower terminal I 4.

Let it be assumed now that a fault occurs in the circuit in which the fuse switch is interposed iii) which :is of sufficient magnitude to rupture the fuse link 42,. .In this event rupture of the fuse link will release the arm 63 from the restraint normally imposed thereon by the intact fuse link and the torsional coil spring 64 swings the forward end portion of said arm downwardly about the pivot rod 62 whereby the lower portion of the ruptured fuse link will be pulled quickly from the tube structure of the fuse cartridge so as to extinguish any electrical .arc which may be formed between the ruptured ends of the fuse link. Also, rupture .of the fuse link permits the torsional coil spring '60 to swing the rear end portion of the latching element 58 downwardly about the pivot rod 51, thereby unlatching the bridge portion 58c of said latching element from the bridge portion 41b of the hinge member 41 and permitting said hinge member to rotate about the hinge elements 50. Such rotation of the hinge member ,4! about the hinge elements 58 results in forward and downward movement of the pivot elements 48 with a consequent lowering of the door and fuse cartridge carried thereby which causes the latching pins 38 to move downwardly out of the keeper portions l9c of the latch member 19 and thus permit the door and fuse cartridge to fall outwardly and downwardly to the open switch position of said assembly, as is shown by broken lines in Fig. 1.

When the improved fuse switch has operated to the open switch position thereof, as is described above, and it is desired to replace the switch in operation in the circuit, the assembly comprised of the door and the fuse cartridge is detached from the housing by lifting the hookshaped portion of the hinge member 41 offof the hinge elements of the housing. The plug 45 is then unscrewed and the upper portion of the ruptured fuse link is removed from the fuse cartridge, the lower portion of the ruptured fuse link also being detached from beneath the link binding element 55. A new fuse link is introduced through the tube structure of the fuse cartridge and the plug 45 is replaced, after which the latch element 56 and arm G3 are moved to their operative positions and the tail portion of the fuse link is secured by the link binding element 55 in position where it retains said latch element and arm in their effective operative positions. The hookshaped portions of the hinge member 47 are reengaged with the hinge elements 50 of the lions ing and the door and fuse cartridge assembly is swung upwardly and inwardly relative to the housing and about the hinge elements 50 into the closed-switch position thereof, as shown in Fig. 1, when the fuse switch is again in service.

I claim:

1. A fuse switch comprising a housing, a door for said housing inovably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, said hinge member comprising opposed side walls which are joined by a bridge portion, a latching element pivotally supported by said door for latching said hinge member against pivotal movement relative to said door, said latching element being retained in a position where it latches said hinge member by the intact fuse link, and latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released by rupture of said fuse'link for movement which unlatches said hinge men:

her and permits hingeing movement of saidhinge member relative tosaid hingeelementes and pivotal movement of said hinge member relative to said door which causes said door and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing.

2. A fuse switch comprising a housing, a door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements fixedly associated with said housing and pivotally attached to said door, said hinge membercomprising opposed side walls which are joined by a bridge portion, a latching element pivotally supported by said door for latching said hinge member against pivotal movementrelative to said door, spring'means associated with said latching element which tends to move said latching element in one direction, said latching element being retained in a position where it latches said hinge member by the intact fuse link, and latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released by rupture of said fuse link for movement which unlatches'said hinge member and permits hingeing movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said door which causes said door and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said hous- 3. A fuse switch comprising a housing, a door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, said hinge member comprising opposed side walls which are joined by an integral bridge portion a latching element pivotally supported by said door for engaging the bridge portion of and latching said hinge member against pivotal movement relative to said door, torsional spring means associated with said latching element which tends to move said latching element in one direction, said latching element being retained in a position where it latches said hinge member by the intact fuse link, and latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released by rupture of said fuse link for movement which unlatches said hinge member and permits hingeing movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said door which causes said door and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing.

4, A fuse switch comprising, a housing, a. door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, a latching element for latching said hinge member against pivotal movement relative to said door, said latching element being shaped to embrace a portion of said fuse cartridge and being-retained in a position where it latches said hinge member by the intact fuse link, latch means for latching the-upper. portion of said door in its closed position relative. to said housing, said latching element being released by rupture of said fuse link for movement which unlatches said hinge member and permits hingeing movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said doorwhich causes said door and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing, and an arm mounted pivotally on said latching element for such movement that it ex tracts a portion of the fuse link from the fuse cartridge on rupture of said fuse link. '5! A fuse switch comprising a housing, a door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and providedwith a fuse link extended therethrough, a' hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, a latching element for latching said hinge member against pivotal movement relative to said door, said latching element being shaped to embrace a portion of said fuse cartridge and being retained in a position where it latches said hinge member by the intact fuse link, latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released'by rupture of said fuse link for movement which unlatches said hinge member and permits hinging movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said door which causes 'said door'and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing, an arm mounted pivotally on said latching element for such movement that it extracts a portion of the fuse link from the fuse cartridge on rupture of said fuse link, and spring means for subjecting said arm to swinging movement. 6. A fuse switch comprising a housing, a door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, a latching element for latching said hinge member against pivotal movement relative to said door, said latching element being shaped to embrace a portion of said fuse cartridge and being retained in a position where it latches said hinge member by the intact fuse link, latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released by rupture of said fuse link for movement which unlatches said hinge member and permits hinging movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said door which causes said door and the fuse cartridge carriedthereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing, an arm mounted pivotally on said latching element for such movement that it extracts a portion of the fuse link from the fuse cartridge on rupture of said fuse link, and torsional spring means for subjecting said arm to swinging movement.

7. A fuse switch comprising a housing, a door for said housing movably supported thereby, a fuse cartridge fixedly supported by said door and provided with a fuse link extended therethrough, a hinge member hingedly supported by hinge elements associated with said housing and pivotally attached to said door, a latching element for latching to said hinge member against pivotal movement relative to said door, said latching element being shaped to embrace a portion of said fuse cartridge and being retained in a position where it latches said hinge member by the intact fuse link, latch means for latching the upper portion of said door in its closed position relative to said housing, said latching element being released by rupture of said fuse link for movement which unlatches said hinge member and permits hinging movement of said hinge member relative to said hinge elements and pivotal movement of said hinge member relative to said door which causes said door and the fuse cartridge carried thereby to move downwardly so as to release said latch means at the upper portion of the door and permit the door and fuse cartridge assembly to swing outwardly and downwardly relative to said housing, an arm engaged by said fuse link and mounted pivotally on said latching element for such movement that it extracts a portion of the fuse link from the fuse cartridge on rupture of said fuse link, and spring means for subjecting said arm to swinging movement.

VERNON HELLSTERN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,073,186 Steinmayer et al. Mar. 9, 1937 2,249,178 Schultz July 15, 1941 2,359,153 Rawlins Sept. 26, 1944 

